The proposed research will be composed of four parts: Part I. Characterization of RNA polymerase II by using analogs of ATP and UTP, i.e., 3'dATP and 3'dUTP. The purpose will be to determine if these 3'- deoxy analogs are competitive inhibitors of RNA polymerase II or if they are actually incorporated into RNA and thereby terminate RNA synthesis. Labeled and unlabeled nucleotides have been prepared in the laboratory. Part II. Elucidation of the RNA primer step in DNA replication by using 3'dUTP. This pyrimidine analog will overcome the problems that arise by using 3'dATP since ATP is required for RNA primer synthesis as well as the energy requiring step in DNA synthesis. Part III. Comparison of ADP-ribosylation of nuclear proteins in rat liver nuclei by using NAD ion analogs with modification in the adenine and/or ribosyl moieties of NAD ion. The study will include the mechanism of covalent bond formation of ADPR and nuclear histones or nuclear proteins. Part IV. Biosynthesis of the C-nucleoside, pyrazomycin. Because of our data on the biosynthesis of minimycin, we are now able to predict that C-nucleoside biosynthesis proceeds via a C-7 sugar. This study will be accomplished with (1-C13) glucose. This glucose already has been synthesized in this laboratory.